First documented in New York in the winter of 2006-07, White-Nose Syndrome is believed to have surfaced in Pennsylvania in 2008 and began killing cave bats in 2009. WNS refers to a white fungus on the muzzles and wing membranes of affected bats. Because this fungus is a cold-loving fungus, it is a condition that only affects them while they hibernate. Therefore, it is not harmful to humans, and does not grow on bats during the summer months or when bats are at typical active temperatures. This fungus has been confirmed to be the causative agent of the disease, although the specific mechanism in how it causes mortality is not fully understood.

The Race to Save Pennsylvania's Bats originally premiered in Pittsburgh on January 23, 2012, as part of WQED's documentary series Experience. The 28 minute video features field packages and interviews with Pennsylvania Game Commission (PGC) Endangered Mammal Specialist Greg Turner and PGC Biologist Cal Butchkoski; biologist among others.

The exact mechanism by which WNS causes mortality is unknown. However, it has been shown that when bats become infected by the causative agent, a fungus called Geomyces destructans, the bats arouse too frequently causing a severe depletion of fat reserves. Although most sites in Pennsylvania have now been contaminated by this fungus, preliminary research in Pennsylvania documents all survivors still become infected annually. It is likely that these few survivors are existing on limited fat reserves, and every disturbance is an additional cost on those reserves. The effect of this disturbance may directly cause mortality later in the hibernation season to adults or juveniles fighting infection, or it may lower the fitness of adult females enough to inhibit their ability to successfully reproduce. Therefore, the Pennsylvania Game Commission strongly recommends that recreational caving not occur at any hibernacula during the months when bats are hibernating (October 1- April 31).